LATEX expects documents to be arranged in a conventional,
hierarchical way, with chapters, sections, sub-sections,
appendixes, and the like. These are marked using macros rather
than environments, probably because the end of a section can be
safely inferred when a section of equal or higher level starts.

There are six ``levels'' of sectioning in the document classes
used for Python documentation, and the deepest two
levels1 are not used. The levels are:

Level

Macro Name

Notes

1

\chapter

(1)

2

\section

3

\subsection

4

\subsubsection

5

\paragraph

(2)

6

\subparagraph

Notes:

(1)

Only used for the manual documents, as described in
section 4, ``Document Classes.''